We intend to learn more about two means of influencing the appropriateness of physician prescribing: through an administrative intervention performed by Medicaid on all physicians in Massachusetts, and through our own personal intervention that we will execute in two other states. Both studies will use a Medicaid dataset for accurate measures of actual prescribing behavior. The first analysis will evaluate data collected in the mass. Medicaid Cost-Effectiveness project in which doctors were sent guidelines condemning use of peripheral/cerebral vasodilator drugs, and in some cases providing feedback of physicians' prescribing records. We will measure prescribing records for each physician before and after these interventions to determine their impact. We hypothesize that attempts to change physician behavior often fail because they do not address the behavioral or organizational aspects of clinical practice. The second study will therefore be the development and testing of an innovative de-marketing strategy based in social psychology, behavioral science and advertising and businss theory as well as pharmacology. We will focus on overprescribing of propoxyphene, cephalexin, and the peripheral/cerebral vasodilators. Physicians in the Vermont and new Hampshire Medicaid programs will be randomly assigned to five groups: control (no intervention), or combination of four experimental interventions: a conventional fact sheet, an arresting series of "un-advertisements," advice on alternatives to using the target drugs, and contact by a professional representative. Before and after Medicaid records of prescribing data will be used to evaluate each component of this intervention as well.